we can do better, obama is right. but we must understand the institutions that caused the problem and the problems. host: a tweet -- how do we strike a balance? you cannot just have homes. you have to have schools and sewer systems and other infrastructure to support the homes. and still need farmland. guest: more than a third of the country's farmland. we have a billion acres of farmland. we only grow crops on 400 million acres of it. about 40% of all of our farmlands. so there's lots of farmland. there's a huge surplus of farm land. we grow a crop surpluses we can export every year. there's no shortage of farms. there's a shortage of homes, especially in places like california, where 95% of the people are confined to about 5% of the state because of urban growth boundaries. there's a shortage of places to build homes. when you drive on in the interstate freeway, you might see a lot of urban sprawl. if you get off the interstate, and we have a tremendous amount of open space and forests and farms in this country, the